One proven strategy to help students make sense of abstract concepts is to sequence instruction so students have exploratory opportunities to investigate science before being introduced to new science explanations (Abraham and Renner 1986; Renner, Abraham, and Birnie 1988). To help physical science teachers make sense of how to effectively sequence lessons, this article summarizes our experiences using an exploration-explanation sequence of instruction to teach Bernoulli's principle to prospective middle and secondary science teachers in a science methods course. We use demonstrations during our Bernoulli unit to help students go back and forth between their observations of phenomenon and what occurs on the microscopic level with what we have termed "molecular talk." Students engage in guiding questions, consider their old and new understandings of science, and use evidence to construct new ideas during all stages of the lesson. (Contains 4 figures and 1 table.)